Intel Core i5-7640X vs Intel Core i7-5775C Comparison

Head-to-Head Benchmarks

The benchmark data paints a surprisingly clear picture: the older Core i7-5775C wins six of the eight head-to-head tests, despite the Core i5-7640X having significantly higher clock speeds. In every Cinebench iteration, the 5775C takes the lead. The margin is consistent, ranging from 8.6% to 9.4% across R15, R20, and R23 in both single-core and multi-core tests. For example, in Cinebench R15 multi-core, the 5775C scores 660 versus 607 for the 7640X, a delta of 8.7%. The single-core R15 result shows a 9.4% advantage (93 vs 85), which is notable because single-thread performance is usually where higher clock speeds dominate.

The pattern repeats in R20, where the 5775C scores 2750 multi-core and 388 single-core, against 2533 and 357 for the 7640X. That is an 8.6% and 8.7% lead, respectively. Cinebench R23 follows the same script: 6549 vs 6031 multi-core (8.6%) and 924 vs 851 single-core (8.6%). The consistency of these deltas across different Cinebench versions suggests a fundamental architectural efficiency advantage for the Broadwell part, not a workload-specific quirk.

However, the story flips entirely in Geekbench. The 7640X wins Geekbench multi-core with 5137 against 4989, a 2.9% margin. The single-core Geekbench result is even more decisive: 1736 vs 1441, giving the 7640X a 17% victory. This is a dramatic reversal. The 7640X, with its 4.30 GHz boost clock versus the 5775C's 3.70 GHz, shows exactly what raw clock speed can do in certain synthetic workloads. Meanwhile, the 5775C's 8.6% to 9.4% Cinebench wins suggest that its Broadwell architecture, with integrated memory controller optimizations, handles rendering-style workloads more efficiently despite lower frequencies.

The average benchmark scores reflect these competing strengths. The 5775C has an average score of 2224, while the 7640X sits at 2167. That places the 5775C slightly ahead overall, though both occupy the 47th percentile among all CPUs in the database. The nearest rivals for the 5775C include the Intel Core i7-8559U with an average score of 2225 (0% delta) and the Intel Xeon E5-4648 v3 at 2227 (-0.1%). For the 7640X, the closest competitor is the Intel Core i5-1145G7E at 2174 (-0.3%), with the AMD Ryzen 5 3400GE also at 2175 (-0.3%).

Where Each One Wins

The 5775C is the clear choice for rendering and multi-threaded productivity, as evidenced by its complete sweep of the Cinebench suite. Every Cinebench test, from R15 through R23, in both single-core and multi-core variants, favors the 5775C by roughly 8.6% to 9.4%. This suggests that the 5775C's 8 threads (4 cores with Hyper-Threading) provide a tangible advantage over the 7640X's 4 threads (4 cores without Hyper-Threading) in threaded workloads. The fact that the single-core Cinebench tests also favor the 5775C, despite the 7640X's higher clock speed, indicates that the Broadwell core is simply more efficient per clock in these specific rendering tasks.

The 7640X wins where memory bandwidth and raw clock speed matter most. Its Geekbench single-core score of 1736 is 17% higher than the 5775C's 1441, a massive gap that points to the 7640X's 4.30 GHz boost clock as the dominant factor. The Geekbench multi-core result (5137 vs 4989) is closer, but still a 2.9% win for the 7640X. This suggests that in integer-heavy, memory-latency-sensitive workloads typical of Geekbench's test suite, the 7640X's Kaby Lake architecture with its higher frequencies pulls ahead.

For users running a mix of workloads, the 5775C's overall average score (2224 vs 2167) suggests it is the more balanced performer. The 7640X, however, may appeal to those prioritizing single-thread responsiveness in applications that resemble Geekbench's scoring model. The data does not support the 7640X as a better all-rounder; it wins only two of eight tests, but those two wins are substantial, particularly the 17% single-core Geekbench margin.

FAQ

Q: Which CPU has the higher boost clock?

A: The Intel Core i5-7640X has a boost clock of 4.30 GHz, while the Intel Core i7-5775C boosts to 3.70 GHz.

Q: Does the Core i7-5775C have more threads than the Core i5-7640X?

A: Yes. The 5775C has 8 threads (4 cores with Hyper-Threading), while the 7640X has 4 threads (4 cores without Hyper-Threading).

Q: Which CPU performs better in Cinebench R23 multi-core?

A: The Core i7-5775C scores 6549, which is 8.6% ahead of the Core i5-7640X's 6031.

Q: What is the largest benchmark margin between the two?

A: The largest margin is in Geekbench single-core, where the Core i5-7640X scores 1736 versus 1441 for the 5775C, a 17% difference.

Q: Do both CPUs support ECC memory?

A: No. Both the 5775C and the 7640X have ECC memory support set to false in the database.

Q: Which CPU has a higher average benchmark score?

A: The Core i7-5775C has an average score of 2224, while the Core i5-7640X averages 2167.

Specification Differences

The two processors differ in several fundamental specifications. The 5775C has 4 cores and 8 threads, while the 7640X has 4 cores and 4 threads. Base clocks are 3.30 GHz for the 5775C and 3.90 GHz for the 7640X, with boost clocks of 3.70 GHz and 4.30 GHz respectively. Thermal design power differs substantially: the 5775C is rated at 65 watts, whereas the 7640X consumes 112 watts. This is a 47-watt gap that reflects the 7640X's higher operating frequencies.

Memory support separates them clearly. The 5775C uses DDR3 memory with a dual-channel bus and a measured memory bandwidth of 25.6 GB/s. The 7640X uses DDR4 memory with a quad-channel bus, though the database does not record a bandwidth figure for it. The sockets are incompatible: the 5775C uses Intel Socket 1150, while the 7640X uses Intel Socket 2066. Both have unlocked multipliers, but the 5775C includes integrated graphics (Iris Pro Graphics 6200), while the 7640X has no integrated GPU at all.

PCIe connectivity also differs. The 5775C provides Gen 3 with 16 lanes (CPU only), while the 7640X lists Gen 3 without a specified lane count. Release dates are roughly two years apart, with the 5775C launching on 2015-05-14 and the 7640X on 2017-06-25. The 5775C has a recorded launch MSRP of $366, while no launch MSRP is recorded for the 7640X.

Architecture Differences

Both CPUs are built on Intel's 14 nm process node, but they represent different architectures. The 5775C is based on Broadwell, the fifth-generation Core architecture, while the 7640X is based on Kaby Lake, the seventh-generation architecture, specifically the Kaby Lake-X variant. The database lists the 5775C's codename as "Broadwell" and its generation as "Core i7 (Broadwell)", while the 7640X is codenamed "Kaby Lake-X" with the generation "Core i5 (X-Series 7th Gen)".

Cache layouts are identical in structure: 64 KB L1 per core, 256 KB L2 per core, and 6 MB shared L3. However, the architectural implementations differ. Broadwell was a die-shrink of Haswell with improved memory controllers and integrated graphics, which likely explains the 5775C's efficiency in Cinebench despite lower clocks. Kaby Lake-X is a derivative of Kaby Lake optimized for the high-end desktop platform, which explains its higher clock speeds and quad-channel memory support.

The 5775C's integrated Iris Pro Graphics 6200 is a significant architectural feature that the 7640X completely lacks. The 5775C also has a recorded die size of 182 mm², while the 7640X has no die size recorded. The 5775C's part number is SR2AG, while the 7640X has no part number listed. The 5775C's production status is "Active", while the 7640X has no production status recorded. These differences indicate that the 5775C was designed as a mainstream desktop part with integrated graphics, while the 7640X was built for the enthusiast X-series platform with external graphics required.

The Verdict

The data consistently favors the Core i7-5775C in rendering workloads and overall average performance. Its six benchmark wins, all in Cinebench, come with margins between 8.6% and 9.4%, and its average score of 2224 surpasses the 7640X's 2167. For users running Cinebench-style applications, which typically represent 3D rendering and content creation, the 5775C is the stronger choice despite its lower clock speeds and older architecture. The 65-watt TDP also makes it a more power-efficient option, though the database does not provide efficiency metrics for direct comparison.

The Core i5-7640X is not without merit. Its Geekbench single-core score of 1736 is 17% higher, a commanding lead that indicates superior performance in certain single-threaded, memory-latency-sensitive tasks. The 7640X also wins Geekbench multi-core by 2.9%, suggesting that in integer-heavy workloads, its higher clocks and quad-channel DDR4 memory support compensate for the lack of Hyper-Threading. Users who prioritize single-thread responsiveness, or who run applications that behave like Geekbench's tests, should consider the 7640X.

However, the 7640X's overall profile is weaker. It loses the majority of head-to-head tests, occupies the same 47th percentile among all CPUs, and has a lower average score. Its 112-watt TDP is substantially higher, and it lacks integrated graphics, requiring a discrete GPU for any display output. The 5775C, with its integrated Iris Pro Graphics 6200, offers a more complete package for a desktop system.

The verdict is straightforward: for balanced performance, rendering workloads, and power efficiency, the Core i7-5775C is the better choice. For users who need maximum single-thread performance in Geekbench-like scenarios and are prepared to accept higher power draw and no integrated graphics, the Core i5-7640X has a specific, narrow appeal. The benchmark record shows the 5775C as the more versatile processor, winning the majority of tests and posting a higher average score.